1. Field of the Invention
The present invention relates to a semiconductor device.
2. Description of the Related Art
In recent years, a technique for achieving high integration of a semiconductor device by stacking element groups having a plurality of semiconductor elements manufactured using different substrates or mounting the element groups on the same package has been developed. As for such a semiconductor device, in a step of stacking the element groups or a step of mounting the element groups on the same package, it should be considered that an element which has been already formed is not damaged by heat, a chemical, or the like. As for manufacturing of a MEMS structure, transformation, deterioration, or the like due to heat, a chemical, or the like in a step of stacking element groups or a step of mounting element groups has been greatly problematic as a cause of decrease in yield. Note that here, an element group corresponds to a micro electro mechanical system (hereinafter referred to as a MEMS structure) manufactured using micromachining technology, and the like.
In addition, causes of decrease in yield are different between a MEMS structure manufactured using micromachining technology and a semiconductor integrated circuit which is manufactured by conventional technology for manufacturing an LSI and is provided around a MEMS structure. Therefore, in a micromachine having such a MEMS structure and a semiconductor integrated circuit, it is difficult to improve productivity because even if the micromachine is an on-chip type where the semiconductor integrated circuit and the MEMS structure are provided over the same substrate or an on-package type where the semiconductor integrated circuit and the MEMS structure are provided over different substrates and are mounted on the same package, yield thereof is the product of yield of the MEMS structure and yield of the semiconductor integrated circuit.
Nowadays, a MEMS structure and a semiconductor integrated circuit are often manufactured through different steps and are mounted using an on-package type. In order to electrically connect element groups manufactured over different substrates, wire bonding is commonly used and resin sealing is performed after connection.
In the case where a MEMS structure and a semiconductor integrated circuit are manufactured through different steps and are mounted by bonding substrates, it is difficult to seal a sealed space closely and to form a terminal for electric connection (for example, see Reference 1: Japanese Patent No. 3808092). Further, when a MEMS structure and a semiconductor integrated circuit are connected using a wiring, there has been a problem in that yield is decreased due to disconnection.
On the other hand, in the case where another element group (an antenna, a sensor, or the like) is mounted on a semiconductor integrated circuit, the biggest problem in reliability is fluctuation in impedance of a mounted portion. If the worst happens, impedance is opened.